Active smoking and COPD phenotype: distribution and impact on prognostic factors

Figures & data

Figure 1 Diagnostic algorithm of the clinical phenotypes.

Note: Adapted from Miravitlles M, Soler-Cataluña JJ, Calle M, et al. Spanish COPD Guidelines (GesEPOC): Pharmacological treatment of stable COPD. Arch Bron coneumol. 2012;48(7):247–257, with permission from the Sociedad Española de Neumología y Cirugía Torácica (SEPAR).³
Abbreviations: COPD, chronic obstructive pulmonary disease; MCAP, mixed COPD-asthma phenotype; ACOS, asthma-COPD overlap syndrome; PBD, bronchodilator test.

Table 1 Characteristics of the whole study population and stratification by smoking habit

Variables	Total population	Active smokers	Non smokers	P-value
Sex (n, %)
Male	1,314 (82.1)	738 (56.2)	574 (43.8)	0.39
Female	286 (17.9)	152 (53.3)	133 (46.7)
Age (years)	66.7 (66.2–67.2)	67.0 (66.4–67.7)	66.3 (65.6–67.0)	0.12
BMI (kg/m^2)	27.9 (27.6–28.1)	27.7 (27.4–28.0)	28.1 (27.7–28.4)	0.10
Dyspnea grade	1.8 (1.7–1.8)	1.8 (1.8–1.9)	1.7 (1.6–1.8)	0.003
Spirometry
FVC (L)	2.5 (2.4–2.6)	2.5 (2.4–2.6)	2. 5 (2.4–2.6)	0.89
FVC (%)	73.5 (72.7–74.2)	73.4 (72.3–64.4)	73.6 (72.7–74.2)	0.75
FEV1 (L)	1.3 (1.3–1.4)	1.4 (1.3–1.4)	1.3 (1.3–1.4)	0.56
FEV1 (%)	54.7 (53.9–55.5)	54.2 (53.1–55.4)	55.3 (54.1–56.5)	0.18
FEV1/FVC	55.4 (54.7–56.0)	55.2 (54.3–56.1)	55.5 (53.9–55.5)	0.64
CAT score	22.0 (21.4–22.7)	20.5 (19.6–21.4)	23.3 (22.5–24.1)	<0.001
BODEx	2.7 (2.6–2.8)	2.8 (2.7–3.0)	2.7 (2.5–2.8)	0.15
Number of comorbidities	2.0 (1.9–2.1)	2.1 (2.0–2.2)	1.9 (1.8–2.0)	0.07

Note: Data presented as mean (95% confidence interval), unless otherwise stated.

Abbreviations: CI, confidence interval; BMI, body mass index; FVC, forced vital capacity; FEV₁, forced expiratory volume in 1 second; CAT, COPD assessment test; BODEx, body mass index, airflow obstruction, dyspnea and exacerbations.

Table 2 Patient characteristics and COPD severity according to phenotype and smoking habit

Variables	Non-exacerbators	ACOS	Exacerbators with emphysema	Exacerbators with chronic bronchitis
Sex (n, %)
Male	618 (47.9)	167 (13.0)	209 (16.2)	296 (22.9)
Female	117 (42.2)	60 (21.7)	48 (17.3)	52 (18.8)
Age (years)	66.2 (65.5–67.0)	64.8 (63.5–66.2)	67.9 (66.7–69.0)	68.1 (67.1–69.1)
Spirometry
FVC (L)	2.6 (2.5–2.7)	2.5 (2.3–2.7)	2.3 (2.2–2.4)	2.3 (2.2–2.4)
FVC (%)	74.4 (73.3–75.5)	75.1 (73.1–77.1)	71.3 (69.2–73.4)	72.1 (70.4–73.7)
FEV1 (L)	1.4 (1.4–1.5)	1.4 (1.3–1.5)	1.1 (1.1–1.2)	1.3 (1.2–1.3)
FEV1 (%)	56.6 (55.4–57.7)	60.8 (58.8–62.8)	46.6 (44.6–48.6)	52.6 (50.9–54.2)
FEV1/FVC	56.0 (55.1–56.9)	60.0 (58.4–61.7)	49.3 (47.6–51.0)	55.3 (54.0–56.6)
Smoking habit (n, %)
Active smokers	401 (54.6)	112 (48.9)	152 (58.9)	203 (57.7)
Non-active smokers	334 (45.4)	117 (51.1)	106 (41.1)	149 (42.3)
Dyspnea grade
Active smokers	1.5 (1.4–1.6)	1.7 (1.5–1.9)	2.3 (2.2–2.5)	2.2 (2.1–2.3)a
Non-active smokers	1.4 (1.3–1.5)	1.6 (1.5–1.8)	2.3 (2.1–2.4)	1.9 (1.8–2.0)
CAT score
Active smokers	16.6 (15.4–17.8)a	24.0 (22.1–26.5)	24.6 (22.7–26.5)	23.5 (21.4–25.7)a
Non-active smokers	20.0 (18.9–21.1)	25.3 (23.4–27.2)	26.8 (24.7–28.9)	26.8 (25.0–28.6)
BODEx
Active smokers	2.1 (1.9–2.3)	2.2 (1.8–2.6)	4.2 (3.9–4.6)	3.5 (3.2–3.8)
Non-active smokers	2.0 (1.8–2.2)	2.3 (2.0–2.7)	4.3 (4.0–4.7)	3.2 (2.9–3.5)
Number of comorbidities
Active smokers	1.7 (1.6–1.9)	2.1 (1.9–2.3)	2.1 (1.4–2.4)	2.7 (2.5–2.9)a
Non-active smokers	1.6 (1.4–1.7)	2.1 (1.8–2.3)	2.5 (1.9–2.4)	2.4 (2.2–2.6)

Notes:

a P<0.05 between active and non-active smokers in each phenotype category. Data presented as mean (95% confidence interval), unless otherwise stated.

Abbreviations: CI, Confidence Interval; ACOS, asthma-COPD overlap syndrome; CAT, COPD assessment test; BODEx, body mass index, airflow obstruction, dyspnea and exacerbations; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity.

Figure 2 Distribution by COPD phenotype.

Abbreviation: ACOS, asthma-COPD overlap syndrome.

Table 3 Factors associated with active smoking in the multivariate analysis

Variables	OR	95% CI	P-value
CAT (11–20 vs 0–10)	1.141	0.769–1.693	0.51
CAT (21–30 vs 0–10)	0.700	0.472–1.038	0.08
CAT (31–40 vs 0–10)	0.301	0.187–0.487	<0.001
BODEx (3–4 vs 0–2)	1.202	0.914–1.581	0.19
BODEx (5–6 vs 0–2)	1.637	1.151–2.328	0.006
BODEx (≥7 vs 0–2)	2.051	1.031–4.080	0.040
Osteoporosis (yes vs no)	1.610	1.145–2.265	0.006

Abbreviations: OR, odds ratio; CI, confidence interval; CAT, COPD assessment test; BODEx, body mass index, airflow obstruction, dyspnea and exacerbations.

Table S1 Description of patient population included in the study

Demographics
	N	NMiss	Median	SD	95% CI Low	95% CI High	Min	Median	Max
Age (years)	1,580	30	66.71	9.67	66.24	67.19	35.00	67.00	92.00
					n				%
Age (years)
35–60					422				26.71
61–65					282				17.85
66–75					560				35.44
+75					316				20.00
Total					1,580				100.00
Sex
Male					1,314				82.13
Female					286				17.88
Total					1,600				100.00
	N	NMiss	Median	SD	95% CI Low	95% CI High	Min	Median	Max
Weight (kg)	1,587	23	77.77	14.53	77.05	78.48	40.00	78.00	183.00
Height (cm)	1,585	25	166.95	7.90	166.56	167.34	130.00	167.00	194.00
BMI (kg/m^2)	1,581	29	27.86	4.72	27.63	28.10	13.52	27.68	68.36
Smoking status	Frequency	%	IC95% Inf %	IC95% Sup %
Smoker	891	55.41	52.98	57.84
Ex-smoker	677	42.10	39.69	44.51
Nonsmoker	40	2.49	1.73	3.25
	1,608	100.00
	N	Median	SD	95% CI Low	95% CI High	Min	Median	Max
Smoking index (pack/year)
Smoker	849	65.02	94.95	58.62	71.41	1.00	40.00	900.00
Ex-smoker	658	61.72	88.56	54.94	68.50	1.00	45.00	800.00
Nonsmoker	0	–	–	–	–	–	–	–
Total	1,507	63.58	92.20	58.92	68.24	1.00	42.00	900.00
Clinical characteristics
	N	NMiss	Median	SD	95% CI Low	95% CI High	Min	Median	Max
Years from COPD diagnosis	1,505	105	8.95	7.93	8.55	9.35	0.00	7.00	89.00
	N	NMiss	Median	SD	95% CI Low	95% CI High	Min	Median	Max
FVC (mL)	1,234	376	2,499.94	869.44	2,451.38	2,548.50	300.00	2,530.00	4,310.00
FVC (%)	1,329	281	73.48	14.37	72.70	74.25	44.00	73.00	106.00
FV1 (mL)	1,236	374	1,350.05	551.87	1,319.26	1,380.85	193.00	1,290.00	2,730.00
FV1 (%)	1,345	265	54.70	15.08	53.90	55.51	26.00	55.00	87.00
FV1/FVC (%)	1,358	252	55.37	12.17	54.73	56.02	27.00	57.00	81.00
					n				%
Dyspnea grade
Grade 0					98				6.15
Grade 1					572				35.88
Grade 2					565				35.45
Grade 3					318				19.95
Grade 4					41				2.57
Total					1,594				100.00
	N	NMiss	Median	SD	95% CI Low	95% CI High	Min	Median	Max
Number of exacerbations in the previous year	1,567	43	0.95	1.25	0.88	1.01	0.00	1.00	10.00
BODEx	1,423	187	2.75	1.93	2.65	2.86	0.00	3.00	8.00
				n					%
BODEx
BODEx 0–2				692					48.63
BODEx 3–4				449					31.55
BODEx 5–6				236					16.58
BODEx ≥7				46					3.23
Total				1,423					100.00
	N	NMiss	Median	SD	95% CI Low	95% CI High	Min	Median	Max
CAT score	1,591	19	20.89	8.93	20.45	21.33	0.00	21.00	40.00
					n				%
COPD impact according to CAT
None					55				3.46
Low					128				8.05
Intermediate					559				35.14
High					614				38.59
Very high					235				14.77
Total					1,591				100.00
Does the patient present comorbidities?
Yes					1,349				83.79
No					261				16.21
Total					1,610				100.00
	N	NMiss	Median	SD	95% CI Low	95% CI High	Min	Median	Max
No comorbidities	1,610	0	2.00	1.42	1.93	2.07	0.00	2.00	7.00
					n				%
No comorbidities
None					261				16.21
1 comorbidity					354				21.99
2 comorbidities					460				28.57
3 comorbidities					306				19.01
+3 comorbidities					229				14.22
Total					1,610				100.00
Comorbidities
Item	N	n	%	95% CI Low	95% CI High
HBP	1,523	958	62.90	60.48	65.33
Diabetes mellitus	1,479	461	31.17	28.81	33.53
Chronic ischemic heart disease	1,448	205	14.16	12.36	15.95
Arrhythmias	1,457	237	16.27	14.37	18.16
Heart failure	1,458	229	15.71	13.84	17.57
Osteoporosis	1,461	263	18.00	16.03	19.97
Dyslipidemia	1,523	853	56.01	53.51	58.50
Dementia	1,433	20	1.40	0.79	2.00
COPD phenotype	Frequency	%	95% CI Low	95% CI High
Phenotype A	736	46.70	44.26	49.14
Phenotype B	229	14.53	12.81	16.25
Phenotype C	258	16.37	14.56	18.18
Phenotype D	353	22.40	20.36	24.43
	1,576	100.00

Abbreviations: BMI, body mass index; BODEx, body mass index, airflow obstruction, dyspnea and exacerbations; COPD, chronic obstructive pulmonary disease; CAT, COPD assessment test; FVC, forced vital capacity; FEV₁, forced expiratory volume in 1 second; HBP, high blood pressure; NMISS, number of missing entries.

MiravitllesMSoler-CataluñaJJCalleMSpanish COPD Guidelines (GesEPOC): Pharmacological treatment of stable COPDArch Bronconeumol201248724725722561012

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